The "Payment Gateway" is the cashier in the store and is also known as a "Merchant Account." This is basically a business credit card account. The payment gateway allows your se store to accept credit cards and transfer money to you. Merchant Accounts are very important and you should also carefully review their services and prices. If you do not get a merchant account you are pretty much limited to papal. Search the web and check out the available shopping carts and payment gateways.
Now what are you going to sell, and where are you going to get it? You can
look every where for the products you want to sell.
How do you know what will sell well? You need to do some market research.
Not everything sells well, including electronics. If you have no preference
on what to sell, find some marketing software that will allow you to
determine which products ell well online.
Next, you will need a source for those products. Assuming you are not making them yourself. The best way is to drop ship them. The trouble is finding a reliable drop ship source and avoiding the imposters.
Once you find you product source you need to open an account and stock your store and start selling. There munch more to an ecommerce store then can be explained in a brief article format. As someone who recently went from zero to an online store , I know first hand of the pit falls that await the beginning ecommerce site builder.
Having an ecommerce shopping cart software program can really contribute a lot to the success of your online business. However, with the many options available in the market today, you have to be very careful when selecting the ecommerce shopping cart software that will best work for your ecommerce site.